Posted
by
samzenpuson Friday August 31, 2012 @12:24AM
from the red-computer-eyes dept.

An anonymous reader writes "Australian researchers implanted a bionic eye with 24 electrodes in Ms Dianne Ashworth, a 54-year-old who had limited vision due to a inherited condition called retinitis pigmentosa. The implant has allowed her to see flashes of light and shapes when researchers deliver electrical pulses to the device. From the article: 'This early prototype consists of a retinal implant with 24 electrodes. A small lead wire extends from the back of the eye to a connector behind the ear. An external system is connected to this unit in the laboratory, allowing researchers to stimulate the implant in a controlled manner in order to study the flashes of light.
Feedback from Ms Ashworth will allow researchers to develop a vision processor so that images can be built using flashes of light. This early prototype does not incorporate an external camera – yet. This is planned for the next stage of development and testing.'"

Note: This is *NOT* vision. This is an uncoordinated stimulation of neurons that is no more vision than poking your eye and seeing flashes of light or knocking yourself on the back of the head and seeing stars. Vision is a far more complicated matter and these investigators that are promoting this bionic chip have ignored or are ignorant of over a decade of research that shows the neurons in the eye change their wiring in response to retinal degenerative disease. When the wiring in the retina changes, it is no longer able to mediate normal retinal signaling...

I don't think they're making any claims about her nerves system being the same as anyone else's; all of the talk in the press release is specifically about dealing with her case. Think about it for a moment—this technology's going to be used for dealing with damaged eyes for a long time much like those of Ms. Ashworth, not healthy optic systems. Perhaps they're taking on a non-minimal test case, but it's really an extremely topical one.

What they are claiming is that the bionic implant will work in a degenerate retina. The substrate circuitry has changed. No chance of it transducing vision... They are either going to have to intervene at an earlier time point (much earlier than most folks realize) or bypass the retina or reconstruct the retina. There is more biology at play here than a simple engineering project.

In the final version, they plan on having an external camera, and stimulating the optical nerve. Presumably this bypasses the retina (or are the retina and optical nerve the same thing? I'm no expert.) Does this sound feasible?
The background to this project is that it builds on previous work in Australia, on cochlea implants.

So, which ganglion cell populations are they going to stimulate? The optic nerve contains from 14-16 classes of ganglion cells that project to different areas of brain. Its a tough tough problem because those ganglion cells and the axons in the nerves project not only to LGN, but also to a large number of subcortical areas like the SCN and tectum. Then what about the remnant signals that may be coming from peripheral regions of the retina (in cases of AMD) and central retina (in cases of RP)?

The background to this project is that a newly elected government held a big "vox poluli" talk fest called 2020 [wikipedia.org], which was to lay out a "big vision" for Australia. A result was the announcement [theage.com.au] of $50 million funding for a bionic eye project. It's entirely possible that there is an element of "gung ho" about it in that a large chunk of money was laid down for a project that made politicians look good and was easy for the public to understand.

Having said that, there are some pretty smart people involved. As an Australian taxpayer, I'd hope that they are aware for the problems you raise and, given the grandness of the project, would plan on addressing such tough, tough problems. Given your area of expertise, maybe you should contact them? There might be some pretty exciting work to be done in collaboration?

Yeah, its easy for people to get enthused about rescuing vision loss. Its an important thing and keeps us working at all hours of the day as hard as we can to understand how the visual system works and how to fix it when it goes wrong. We've published before on this issue and I am sure they are aware of the work. My only concern is when promises are made to patients and expectations are built up that these devices will cure blindness when the biology has not been worked out and the engineering is predica

We'll see... I would have liked to have seen some traditional methods of evaluation in animal models using psychophysics before moving directly to humans. Were I a betting man, I don't think the engineering is up to the biological task right now. A couple decades work already suggests that we don't yet understand how the information is coded to get into the brain.

From work already done, we know that even very minimal vision is a vast improvement in quality of life over no vision. Yes, probing blindly (no pun intended) is quite hackish, but if a person gets something vision like that is useful, that's a fine result.

I would argue that 100% of medical treatments we have today from first aid up are all based on moving ahead without necessarily understanding the biology. For example, we have used aspirin for over a century but only recently gained some idea of how it works. Clearly though, that understanding was flawed since the first attempt to produce a better treatment based on the new understanding gave us vioxx, which didn't work out so well. It was quite a long time from when we figured out setting bones and casting to the time we had any idea how the bone then heals. All we know is that if you put the ends more or less back together and support it for a while, it would heal.

I have no doubt that better understanding of the biology will result in better engineering and ultimately better vision, but meanwhile, there are people who are blind right now. It is important not to let perfect be the enemy of functional.

Meanwhile, the entire point of the work in TFA is to learn more about what is actually required to get functional vision this way. It's certainly a lot less risky than implants directly into the visual cortex (which have been tried with some success).

This is just my point. While I understand that science and engineering has to start somewhere, they have made promises to this woman and done surgery to her, potentially increasing risks for other problems where I would argue there is no hope of "seeing" anything coherent.

Yes, we can do remarkable things with even an 8x8 pixel array, but this approach has no promise of even delivering that to this woman. The electrode cuff on the optic nerve simply stimulates too many neurons that are not coherent and tho

I have to comment here, a lot of what you are saying is coming across as "not invented here" syndrome, which is a bit of a shame.

I'm convinced beyond all doubt that there are qualified people working on this. I'm also convinced they have more than a basic understanding of biology.

I couldn't find anywhere in the article or the linked videos where they had made promises to Ms Ashworth. On the contrary, she seems fully aware, as do the researchers themselves not surprisingly, that this exercise is experimental

I'm not so sure they made the woman any promises other than some sort of visual stimulation (which seems nearly certain to happen even if it's useless).

The approach is admittedly brute force. I get the impression that they intend to map the electrodes out now that they are implanted to work out what is connected where. It is quite possible that some will prove entirely useless. Others might be limited to small stimulation to avoid spillover. Stimulating the SCN might actually prove to be a happy side effect

Disclaimer: I work for one of the organisations in the Bionic Vision Australia consortium. I don't work on the project specifically. I do know several people who do.

BVA is quite a large group of researchers. Some of them are engineers, some are physicists, some are clinicians and some are biologists. I don't know for sure, but I would be willing to bet the group as a whole understands the biology.

they're working on optic nerve transmissions for people that lost total vision due to macular degeneration or other diseases. See this Ted Talk presentation [youtube.com]

Biological eyes encode vision data as electrical impulses sent to our brain; they're trying to reverse engineer the encoded data at the optic nerve level, which will help make prosthetic eyes a reality.

I am familiar with Nirenberg's work. What Nirenberg seems to be missing is that the programming outflow of the retina is altered in retinal disease. ON and OFF channels are substantially altered in retinal disease and the whole programming substrate is altered because the circuitry and programming down to the molecular levels is altered.

Its not all pessimism though as we will need to understand how the normal retina signals and I find her work to be interesting and compelling. Though she is not addressin

There's also psychology involved. How do you think you'd deal with a previously unknown sense? Some people find becoming sighted to be a terrifying and confusing experience, which can even end in suicide [wikipedia.org].

A person who is well adapted to blindness should think very carefully about becoming sighted.

When the wiring in the retina changes, it is no longer able to mediate normal retinal signaling...

My understanding is that this device bypasses the retina completely, and stimulates the optic nerve directly - it is essentially an array of diamond spikes shooting electricity into the optic nerve. They are hoping that they can then retrain someone's brain to "see" images based on the electric signal they supply

Are you saying that the neurons in the brain completely change their behaviour as a retina degrades, making this technique useless? If so, is this true for all forms of retina failure?

As for the neurons changing their behavior, yes... that is exactly what I am saying. It definitely happens in the retina as the retina is reprogrammed and there is some evidence that it happens higher up as well. Though those precise studies have yet to be performed.

So, flashes of light are simply uncoordinated signaling by neurons. Turns out vision is far more complicated than the cochlear system that allows us to engineer bionic solutions for hearing.

OK, I'll feed the troll. Yes, I am acutely aware of Paul Bach-y-Rita's work. You however apparently do not understand the concepts that you are invoking. There is plasticity in neural systems, yes. Plasticity is important in vision, sure. Nobody, *anywhere* has demonstrated that they can generate coherent "visual percepts" in a coordinated fashion with any kind of stimulus. Its far more complicated than hooking up electrodes and stimulating

I've seen some nice advances in the field lately, like the ones in this TED talk [ted.com]. I understood that this was a first implementation of this technology, but you're saying it's more the old "wire a low resolution light sensor directly to the optic nerve and see what happens" that people have been doing for years?

What's happened to previous work in this field? I remember years ago an implant that let a blind man (how blind he was, I do not know) see the equivalent of a monochrome 16x16 image. It allowed for basic shapes and object recognition. This one seems to be a step back. What gives?

You remember correctly, people have been doing this for years. I have no idea why TFA calls this "world first bionic eye", perhaps there is something new about their particular method, although it doesn't sound very impressive compared to other options.

That sounds like the work of William Dobelle, [wikipedia.org] who was probably the true pioneer in the field of bionic vision. However, Dobelle's subject, "Jerry", needed a device consisting of external glasses, a camera, a computer on a waistband and a neural impact to achieve the equivalent of 20/400 vision where as this is (mostly) embedded in a synthetic eye on the user-side with a requirement for some external equipment in the lab. The size of the lab equipment isn't provided though, so it may not even be portable.

This has the trademarks of every other BS medical/science project.
1. promise billions to investors if you succeed
2. pretend that there is no competition and your project is the best
3. lie and lie and lie and lie and lie to keep the funding coming in so the scientists can keep their jobs
4. the entire project collapses when your competition actually invent something, seeing as how they were 5 years ahead of you in the first place
5. try to get a show on the discovery channel